During approximately the past ten years, four different arrangements have been devised of which applicants are aware for permitting silage to be discharged from a silo through the silo chute without dirtying the chute. U.S. Pat. No. 3,709,345 discloses a silo chute which has a vertical dividing wall which separates the interior of the chute into an access passage and a discharge passage. A transfer conduit conducts silage flung into it by a silo unloader across the access passage and into the discharge passage.
U.S. Pat. No. 3,655,245 discloses an arrangement in which an elongate flexible plastic tube is suspended from the end of the discharge chute of the silo unloader and hangs free in the vertical silo chute. As the silo unloader is lowered in the silo the lower end of the flexible plastic tube is cut off. This, then, requires that a new tube be provided each time the silo is refilled.
U.S. Pat. No. 3,699,732 discloses the use of a flexible plastic tube which is hung from the bottom of a transfer conduit and which is either accordion-folded from the bottom up or from the top down as the transfer conduit is lowered in the silo chute, or else which has a slit which may be opened from the bottom toward the top by a zipper to form an opening which may be kept always at approximately the bottom of the silo chute, with the excess tube material being rolled onto a reel outside the bottom of the chute.
U.S. Pat. No. 3,797,625 discloses an arrangement similar to that of 3,709,345 but having a separate rigid pipe in the silo chute instead of a partition dividing the chute.